The invention relates to a fever thermometer with at least one switching section for the adjustment and/or interruption of an electronic connection and with an actuating element.
Conventional fever thermometers operate according to the principle of thermal expansion of liquid bodies or according to the principle of changing the electric resistance of a conductor in dependence on the temperature.
The mercury thermometers, which have been known for a long time, exhibit grave disadvantages despite their widespread usage.
One disadvantage resides in great fragility. In case of breakage, there occurs not only destruction of the fever thermometer, rendering it useless, but the leakage of toxic mercury can also lead to health damage and the glass shards can cause injuries, particularly with children.
Another drawback lies in poor legibility of the mercury column in the thin glass tube.
Although conventional electronic fever thermometers eliminate these disadvantages, they exhibit other deficiencies which heretofore have precluded any appreciable popularity.
The circumstance that the measuring probe is separated from the indicating device has disadvantageous consequences in usage and is expensive. The connecting cable necessary in this arrangement interferes with handling and storage. The indicating device must be held during measurement or somehow deposited, which is in contrast to conventional procedures in measuring body temperature. The known electronic fever thermometers are equipped with push button switches or sliding switches for the activation or deactivation, as well as for calibration control.
These operating elements are unfamiliar and require special instructions.
Another disadvantage of these switches is that they require openings in the casing. Such gaps and openings are undesirable for hygienic reasons and moreover make sterilization impossible.
Another basic deficiency of these conventional switches resides in that they can be accidentally actuated, which normally leads to a discharge of the battery.
The invention is based on the object of avoiding the drawbacks of the conventional switch constructions, specifically as far as their use for electronic fever thermometers is concerned.
This object has been attained according to the invention by providing that the actuating element of the switch comprises at least one mass arranged to be mobile at least to some degree of freedom, wherein this mass in case of movement according to its degree of freedom cooperates indirectly or directly with the switching section and, if a fixedly determined force exerted by the mass has been exceeded, effects switchover of the switching section from a first switching status into a second switching status, the voluntary triggering of the switching process being inducible by acceleration of the mass in correspondence with the direction of the degree of freedom thereof.
Additional advantages of the invention result if the switching section and the actuating element are arranged in a hermetically sealed fashion.
When applied to electronic fever thermometers, all of the disadvantages of the conventional constructions are avoided.
It is possible to construct the appliance in such a way that it satisfies all requirements with respect to hygiene and measuring practice when handled by unskilled personnel as well as in clinical usage.
It is advantageous to combine the measuring probe, the electronic circuit, the switching element, the current supply, and the indicating unit in a preferably hermetically sealed housing; in this connection, it is readily possible to control, by means of the "centrifugal switch", even rather complicated measuring programs.
Thus, for example, with a single operation of the switch, the electronic programming unit (for instance a microprocessor) can switch to battery control and/or to control of calibration status. Upon a further actuation of the switch, the device switches over automatically to temperature measurement, yielding a maximum value indication, which latter can be erased again by another actuation of the switch, the device being reset to a preselected temperature value.
Deactivation of the appliance takes place advantageously after a predetermined time period following the last operation of the switch. Additional features of the invention can be seen from the following description of several embodiments and in connection with the drawings.